A projection apparatus includes a light source, a color wheel module, a light valve, and a projection lens. The color wheel module includes a light filter and a motor. The light filter has a plurality of filtering portions. Different filtering portions can filter out different color lights. The motor drives the light filter to rotate at a high speed. As the light filter rotates, the illumination beam of the light source is sequentially converted into red, green, blue illumination beams after passing through the light filter. The red, green, blue illumination beams then enter the light valve, and are homogenized and converted into an image beam. The image beam is projected onto a screen by the projection lens. The color wheel module is not only applied to a projection apparatus using a high pressure mercury lamp as a light source, but also applied to a projection apparatus using a solid-state light source.
As the imaging processing technique advances, a projection apparatus may achieve a 4K resolution by using digital micro-mirror device (DMD) equipped with an actuator. To match the frequency of the actuator, a symmetrical color wheel is conventionally used, resulting in a reduction in brightness of the projection apparatus. To balance the needs in high resolution and high brightness of the projection apparatus, an asymmetrical color wheel module is conventionally utilized instead, and the rotation speed of color wheel is increased above 7200 r. p. m.
However, the increase in the rotation speed of color wheel causes an increase in the vibration amount of the light filter, the lightweight bracket of the color wheel module, and the like, thereby causing an increase in the overall vibration amount of the projection apparatus. Moreover, the increase in the rotation speed of color wheel causes a wind noise, and the increase in the overall vibration amount of the projection apparatus causes a vibration noise. The operation noise of the projection apparatus is greatly increased due to the wind noise and the vibration noise.
The information disclosed in this “BACKGROUND OF THE INVENTION” section is only for enhancement understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Furthermore, the information disclosed in this “BACKGROUND OF THE INVENTION” section does not mean that one or more problems to be solved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art